December 2020 Discussion

[Typhoon Tip]

26 minutes ago, qg_omega said:

If you like tomorrow’s weather, you are in luck as it’s a carbon copy for New Years

yeah,.. .that is about as anachronistically out of sync relative to any negative NAO as is fluid mechanically imaginably wrong  -

So, the course of least resistance is to go ahead and assume there is no -NAO ... An SPV located in western Ontario moving into that location by D10 really can't happen otherwise.

I don't know if an easterly biased NAO blocking might open up enough R-wave distribution spacing to allow that kind of exotic anomaly ... It seems that's too much either way - and it may be considering the Euro's depth/height bias beyond D5/6 ...  But given to the horrible handling of the NAO ... now going on what 16 years of modeling ... it almost seems easier assume it doesn't exist.  I dunno -

[Damage In Tolland]

3 minutes ago, weathafella said:

I think the pack hangs on.

Drunk?

[CoastalWx]

6 minutes ago, weathafella said:

I think the pack hangs on.

Toast

[CoastalWx]

3 minutes ago, Damage In Tolland said:

Drunk?

Crown?

[MaineJayhawk]

3 minutes ago, Damage In Tolland said:

Drunk?

After retirement, what else is there to do but drink?

[Typhoon Tip]

I don't think there's going to be much left outside of driveway sides and curb berms ...

This snow is still rather gossamer and flaky.  You need some Italian ice to really lock in frozen actual mass - more mass requires more thermal input to change phase, so that is why a moisture dense icier snow pack is 'somewhat' more resistance to this sort of 9 hour siege of fire hosing.  

Saturation at 52 DPs being pelted along by white noise is likely to do two things....  obliterate all field snow ... roll steam plumes off snow banks...

[RUNNAWAYICEBERG]

4 minutes ago, MaineJayhawk said:

After retirement, what else is there to do but drink?

Chew on edibles and play golf maybe...pretty much it. 

[tamarack]

1 hour ago, 40/70 Benchmark said:

So far, I'd take last season over this year....the one big event didn't pork me.

Still some hope for January, but something needs to show up sooner rather than later IMO.

Same here - had 6" more snow season-to- date with a 7" event coming on New Year's Eve.  Also had plenty of cold thus solid lake covering for ice fishing.  I doubt anything larger than 10 acres will have ice after tomorrow night and Friday.

[weathafella]

23 minutes ago, Damage In Tolland said:

Drunk?

Even though I’m retired I avoid drinking during the week.   Probably right-18 hours of dews AOA 50 with heavy rain isn’t a snow retention recipe.

[Ginx snewx]

31 minutes ago, RUNNAWAYICEBERG said:

Chew on edibles and play golf maybe...pretty much it. 

Ah you will see how time slows down, stress leaves, you do what you want when you want, no alarm clock, no kids to watch, its amazing, like being a kid again. Seriously! I am having fun, little detour but back on the horse.  Life is great.

[Ginx snewx]

15 minutes ago, weathafella said:

Even though I’m retired I avoid drinking during the week.   Probably right-18 hours of dews AOA 50 with heavy rain isn’t a snow retention recipe.

Wind and dews and poof.This is NOHRSC for my station 

[mahk_webstah]

Was walking  all over the fields and into the woods today.  Basically open exposed-to-sun fields have 8-12, less sunny fields 10-14, woods probably 12-16.  It isn't the fluff it once was, very compressed and dense now.  I expect the sunny parts of the fields to be green/brown by Friday afternoon but to retain snow elsewhere.  Will be happy to see our 1500' driveway which goes up a hill, be clear.  I was feelling very envious reading the zones from MSP Erie and Western NY.  but of course I have nothing to complain about...

[Allsnow]

1 hour ago, CoastalWx said:

This looks a lot better than last year did at this time.  Not even close. Sure maybe we roll snake eyes, but this isn’t last year. 
 

I already enjoy this year better. A great Halloween and a big snow with no Ptype issues. A win.

Yeah, imby fetishes aside we are in such a better spot then last winter. The Atlantic looks great and the vortex will remain week. This time last year we were basically ended winter once the vortex gained strength 

[mahk_webstah]

New from CPC and not encouraging, although the 8-14 day sounds more encouraging with systems moving into some troughing over the central and eastt:

US Hazards Outlook
NWS Climate Prediction Center College Park MD
300 PM EST December 23 2020

Synopsis: The forecast circulation during Week-2 continues to feature mid-level high pressure near the West Coast that extends northward through mainland Alaska, with mid-level low pressure over the Great Lakes and Bering Sea. Another area of mid-level high pressure is forecast south of Greenland. Surface low pressure is forecast to be intensifying near the Great Lakes at the start of the period, before shifting east of North America. During the middle to late portion of the forecast enhanced moisture from the Pacific may take aim at parts of the West Coast.

Hazards

• Slight risk of heavy precipitation for much of the eastern U.S., Thu, Dec 31.
• Slight risk of high winds shifting eastward with time from the Northern and Central Plains through the Northeast, Thu-Fri, Dec 31-Jan 1.
• Slight risk of heavy precipitation (mostly rain, with high-elevation snow) for portions of the Pacific Northwest, Northern California, and the Sierra-Nevadas, Sat-Wed, Jan 2-6.
• Slight risk of high winds for portions of the Pacific Northwest and Northern California, Sat-Wed, Jan 2-6.

Detailed Summary

For Saturday December 26 - Wednesday December 30: WPC Days 3-7 U.S. Hazards

For Thursday December 31 - Wednesday January 06: Both the tropics and extratropics are likely to have a role in shaping precipitation over North America during Week-2. La Nina continues to dominate the observed circulation and conditions over the Pacific, with the Week-2 mean 500-hPa height anomalies showing a robust positive Pacific-North American (PNA) pattern among the various ensemble suites. This supports extension of the jet across the Pacific, bringing heavy precipitation and high wind concerns to parts of the West. Over the Atlantic, the 500-hPa height anomalies project strongly onto the negative phase of the North Atlantic Oscillation. A blocking ridge is forecast in the full-field 500-hPa heights south of Greenland, which would historically help lock in colder air upstream over eastern Canada and the Northeast. Despite this favorable pattern, limited cold air appears built up over the higher latitudes of North America, much to the dismay of snow-lovers along the East Coast.

At the beginning of Week-2 model guidance shows a deepening surface cyclone likely to be lifting northeastward from the Middle Mississippi Valley to the Great Lakes downstream of a mid-level trough. Earlier in the week there were some indications this system could redevelop off the Carolinas as a "Miller-B" nor'easter, although models have backed off this solution and are instead keeping the disturbance away from the coastal baroclinic zone. Despite the lessened concern from a system remaining over land while impacting the U.S., the origins of the disturbance fairly far south should help the feature tap into moisture from the Gulf of Mexico. This yields a slight risk for heavy precipitation (generally rain, outside of the highest elevations and portions of the Northeast) for much of the Appalachians, Mid-Atlantic, and Northeast on New Year's Eve. With a tightening pressure gradient forecast on the back side of the surface low, an eastward shifting slight risk for high winds is posted on New Year's Eve and New Year's Day from the Northern and Central Plains eastward through the Northeast. Sustained winds could exceed 30 mph, while also triggering reduced visibility due to blowing snow for areas that saw frozen precipitation from the system.

The positive PNA projection is likely to help advect Pacific moisture into the Pacific Northwest during the middle to end of Week-2. This results in a slight risk of heavy precipitation (generally rain, with snow for higher elevations of the Cascades and Sierra-Nevadas) during January 2-6. This is supported by calibrated reforecast guidance from both the GEFS and ECMWF ensembles showing a better than 20% of the 85th climatological percentile of precipitation being exceeded. Similar probabilities exist for at least 2 inches of liquid equivalent precipitation along the immediate coast and windward facing slopes of the higher terrain during this period. The GEFS is the more bullish of the two models in terms of atmospheric river potential and coverage, with highest chances on the 3rd through 5th (generally poleward of the Oregon/California border). The ECMWF has a firmer boundary for atmospheric river chances south of this region, with its overall probabilities more muted. Since atmospheric river events historically are tied to much of the high wind hazards across the west, and additional support from reforecast guidance, an accompanying slight risk for high winds is posted on January 2-6 for coastal portions of Northern California, Oregon, and Washington state.

Southerly flow is forecast across Alaska, resulting in above-normal temperatures favored for the state during Week-2. Reforecast tools show mixed wet and dry signals over southern portions of the state, although the probabilities for enhanced precipitation are fairly muted when present. Models show periodic disturbances over the Bering Sea and Gulf of Alaska during the forecast period, although these features are often displaced in time and space from run-to-run and model-to model. Given the poor predictability, no associated precipitation or wind hazards are noted at this time.

Forecaster: Daniel Harnos

 

8-14 DAY OUTLOOK FOR DEC 31, 2020 - JAN 06, 2021  
 
The week-2 500-hPa geopotential height pattern looks to feature eastward  
propagation, with weak troughing across the central and eastern CONUS. Near to  
below normal heights are forecast across much of the central and eastern CONUS,  
with the exception of Northern New England. Troughing is forecast to persist  
across the Bering Sea and western Mainland Alaska, favoring negative height  
anomalies for Alaska. Weak ridging favors near to slightly above normal heights  
over the western CONUS. 
 
With the troughing in place over much of the CONUS, the week-2 temperature  
forecast favors near to below normal probabilities across the southern tier of  
the U.S. However, there is some uncertainty over the Southwest, where the  
reforecast guidance is warmer than the uncalibrated guidance. Probabilities of  
above normal temperatures are favored across the northern tier of the CONUS,  
consistent with the above normal 500-hPa heights. Ridging along the West favors  
increased probabilities of above normal temperatures for coastal areas of the  
Pacific. Persistent troughing over the Bering Sea favors a continuation of  
southerly flow and increased above normal temperature probabilities over much  
of Alaska.  
 
Mean troughing over the central and eastern CONUS favors periodic shortwave  
disturbances propagating through the mean flow, bringing increased  
precipitation chances over the eastern CONUS. Below normal precipitation  
probabilities are increased for the Southwest, Rockies, Great Plains and  
western Great Lakes, behind the mean trough axis and underneath anomalous  
northwesterly mid-level flow. Precipitation chances are forecast to increase  
across the Pacific Northwest, as depicted in the GEFS reforecast tool.  
Troughing across the western Gulf of Alaska favors increased near to above  
normal precipitation probabilities across southeastern Mainland Alaska and the  
Panhandle, with ridging favoring increased odds of below normal precipitation  
across central and western parts of the Mainland. 
 
The official 8-14 day 500-hPa height blend consists of: 20% of Today's 0z GFS  
Ensemble Mean centered on Day 11, 20% of Today's 6z GFS Ensemble Mean centered  
on Day 11, 40% of Today's 0z European Ensemble Mean centered on Day 11, and 20%  
of Yesterday's 12z European Ensemble Mean centered on Day 10  
 
 
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: Below average, 2 out of 5, due to  
increasing uncertainty in the mid-level height pattern in the week-2 period,  
combined with weak and conflicting temperature and precipitation signals in the  
guidance. 
 
FORECASTER: Qin Z 
 

[Typhoon Tip]

1 hour ago, CoastalWx said:

This looks a lot better than last year did at this time.  Not even close. Sure maybe we roll snake eyes, but this isn’t last year. 
 

I already enjoy this year better. A great Halloween and a big snow with no Ptype issues. A win.

Great expectations  ?  

I'm at 19.5" of snow here to date, which goes without saying is above normal.  Obviously timing is everything...  If we'd gale whack the hell outta the region two weeks ago, and then hit that fluffy snow storm tomorrow...  tenor changes -

 

[Typhoon Tip]

I disagree with that assessment re La Nina continues to dominate - ... causally?  I think the boreal hemispheric circulation is presently passing through, thus, 'mimicking' La Nina and is ephemeral ...in wait of next week when it doesn't yet again look that way, like so many times over the last 50 days. 

I just feel like there is an agenda to force the perception to lock into an ENSO signal that's not really there - ... just an opinion, and it probably is wrong so chill out. But I have been carefully noting over the last two warm ENSOs,. and the intervening modest cool one, a lack of truer coupling to the ENSO states -

this was even noted by papers and NCEP themselves in the NINO discussions during the last warm phase, when it took untl the end of February for said coupling to demo.  We have also seen ( anecdotally...) this year on numerous occasions October through early/mid Dec, more times than not the circulation not looking very La Nina like...  So, when the writer states, "...continues to dominate..." that leaves me a bit nonplussed -  

[weathafella]

18 minutes ago, Typhoon Tip said:

Great expectations  ?  

I'm at 19.5" of snow here to date, which goes without saying is above normal.  Obviously timing is everything...  If we'd gale whack the hell outta the region two weeks ago, and then hit that fluffy snow storm tomorrow...  tenor changes -

 

Did you get screwed last week?  I mean I’m just inside 128 with 21.4....

[Typhoon Tip]

Just now, weathafella said:

Did you get screwed last week?  I mean I’m just inside 128 with 22 and change....

Screwed  lol ... nah, not taking that bate -

I will say, if you mean not getting 22" ... I did not get that much- but I got 12.5" which ...you know, when did 12" of snow become some kind of forsaken romance tragedy ... 

[weathafella]

2 minutes ago, Typhoon Tip said:

Screwed  lol ... nah, not taking that bate -

I will say, if you mean not getting 22" ... I did not get that much- but I got 12.5" which ...you know, when did 12" of snow become some kind of forsaken romance tragedy ... 

No I actually edited.  My season total is 21.4 thanks to 5.1 10/30, 2 on 12/5, 14.1 on 12/16-17, 0.2 on 12/20.

[78Blizzard]

44 minutes ago, mahk_webstah said:

New from CPC and not encouraging, although the 8-14 day sounds more encouraging with systems moving into some troughing over the central and eastt:

US Hazards Outlook
NWS Climate Prediction Center College Park MD
300 PM EST December 23 2020

 

• Slight risk of heavy precipitation for much of the eastern U.S., Thu, Dec 31.
• Slight risk of high winds shifting eastward with time from the Northern and Central Plains through the Northeast, Thu-Fri, Dec 31-Jan 1.

 

I wonder what they mean by "slight risk"? 

[moneypitmike]

1 hour ago, mahk_webstah said:

New from CPC and not encouraging, although the 8-14 day sounds more encouraging with systems moving into some troughing over the central and eastt:

 

Well, we have lengthening days and increasing sun angle to look forward to.

[mahk_webstah]

Just now, moneypitmike said:

Well, we have lengthening days and increasing sun angle to look forward to.

when the days get longer the cold gets stronger

[Spanks45]

18z GFS shows the New Years Eve storm turning into a SWFE...might slowly keep pushing south as the block starts to exert it's force, watch it end up too far south in the end and we end up high/dry and cold...

[Typhoon Tip]

1 hour ago, weathafella said:

No I actually edited.  My season total is 21.4 thanks to 5.1 10/30, 2 on 12/5, 14.1 on 12/16-17, 0.2 on 12/20.

Gotcha... yeah... and actually, not that you or anyone cares for this opinion but I'm actually quite impressed with this season so far.  In fact, if for some quirky reason the 29th comes back to haunt us, and we add?    We're killin' it!  ...but as is, I'd be happy ending Dec at 19 and change ...( and I bet we get 21 or '2 somehow some way ), we're doing fine.

Look, I get it folks.  It sucks to time a 9 hour deliberate assault on the one day of year people vest a currier&ives nostalgia around snow and apple cheeks and egg nog and icicles and hot chicks in elf costume ...But I'm lucky in that 2/3rds of my Xmas' have only ever had the hot chicks in elf costumes  

yeah right... ...I don't carry along expectations for snow on the ground or in the air on that day ...Cutter storms or warm intrusions in the winter are part of life even in New England -  it just happens and think of it as a gift, because if you want bigger storms, you have to reset the pattern at some point(s) in time(s).

[Damage In Tolland]

4 minutes ago, Spanks45 said:

18z GFS shows the New Years Eve storm turning into a SWFE...might slowly keep pushing south as the block starts to exert it's force, watch it end up too far south in the end and we end up high/dry and cold...

I think that’s how that one will go. Has potential with the block fully in place 

[RUNNAWAYICEBERG]

2 hours ago, Ginx snewx said:

Ah you will see how time slows down, stress leaves, you do what you want when you want, no alarm clock, no kids to watch, its amazing, like being a kid again. Seriously! I am having fun, little detour but back on the horse.  Life is great.

Yea. I’m looking forward to it. Only 20 years to go, hopefully less... once the savings increase when these damn kids get out of daycare. 

[Typhoon Tip]

Seriously.. .does anyone have the EPS NAO ??

[PhineasC]

Still in the mix here for a few inches from the weak event middle of next week. 

[STILL N OF PIKE]

11 minutes ago, PhineasC said:

Still in the mix here for a few inches from the weak event middle of next week. 

If that event cuts west , things may get squirrelly in Randolph , w a NYE cutter in works 

[ORH_wxman]

36 minutes ago, Typhoon Tip said:

Seriously.. .does anyone have the EPS NAO ??

I don’t have the index numbers but the hemispheric H5 pattern is about as staunchly pro-blocking in the NAO/AO region as I have seen it at this lead time since the 2010-2011 winter. Hard to get an ensemble mean this bullish out at 12-15 days.